Cyclotriphosphazatriene-derivatives as soil urease activity inhibitors

ABSTRACT

Tests show that 2,2,4,4,6,6-hexaaminocyclotriphosphazatriene, 2-phenoxy-2,4,4,6,6-pentaaminocyclotriphosphazatriene, 2,4-diphenoxy-2,4,6,6-tetraaminocyclotriphosphazatriene and 2,4,6-triphenoxy-2,4,6-triaminocyclotriphosphazatriene (also frequently called phosphonitrilic derivatives) of the formula ##STR1## are highly effective inhibitors of urease activity in agricultural soil systems wherein 
     (1) R 1  . . . R 3  &#39;=NH 2  or 
     (2) R 1  &#39;=R 2  &#39;=R 3  &#39;=R 2  =R 3  =NH 2  and R 1  =OC 6  H 5  or 
     (3) R 1  &#39;=R 2  &#39;=R 3  &#39;=R 3  =NH 2  and R 1  =R 2  =OC 6  H 5  or 
     (4) R 1  &#39;=R 2  &#39;=R 3  &#39;=NH 2  and R 1  =R 2  =R 3  =OC 6  H 5   
     The above-mentioned compounds and mixtures of the compounds show sustained inhibition of the soil urease activity for periods of at least 21 days.



